Key points are: * Since the matrix A is (potentially) too big to fit into the memory of one node, it is important to allocate it only to blocksize NB<< absolute dimension M: -> complex*16 :: A(nb,nb) * The 1-dimensional array W which contains the eigenvalues IS of absolute size: -> double precision:: w(M) * the eigenvalues w(1..M) are the just available at the "headnode" myrow=0 and mycol=0